Reconciliation and Anomaly Checks

A ferry company's card processor sends a settlement file every morning. For day 35, the file lists 1,395 payments worth 3,292,200 cents. The warehouse table built from the company's own ticket system holds 1,391 payments worth 3,282,050 cents for the same day. The gap is 4 payments and 10,150 cents, which is about 0.29 percent of the payments and 0.31 percent of the money.

A gap that small could be dropped rows, or payments that the two systems place on different days. Comparing the same totals from two systems that should agree, and explaining every difference, is called reconciliation